During his daily press briefing Tuesday, White House Press Secretary Sean Spicer said there was nothing inappropriate about the discussions that took place between former national security adviser Michael Flynn and the Russian ambassador regarding sanctions.

Flynn announced his resignation Monday night after misleading Vice President Mike Pence about the conversations he had with the Russian ambassador before the inauguration.

"The key point in this isn't that there were discussions," Spicer said. "There was nothing wrong or inappropriate about those discussions. It purely came down to a matter of trust."

Spicer said President Donald Trump was not aware of Flynn's conversations while he was NSA-designate.

"He's not back-briefed on every conversation that the national security team has or other staffers," Spicer said of the president.

Spicer said once Trump was made aware of the situation, he immediately asked the White House counsel for further information, ultimately leading him to ask Flynn for his resignation.

When asked if the administration is undertaking any efforts to delve into situations in which anyone has communications with Russia regarding sanctions, Spicer said there is "no other information" and this was an "isolated incident."

Watch the above and below videos for more from Spicer's tense press briefing.

NEW INFO: Flynn Surveillance Required Approval at Highest Levels

Krauthammer on Flynn Controversy: Trump 'Loses One Way or Another'

Kellyanne Conway: Flynn's Resignation the Result of a 'Cumulative Effect'

Trump on Flynn Resignation: 'So Many Illegal Leaks Coming Out of Washington'